Methods of forming aluminum-comprising physical vapor deposition targets; sputtered films; and target constructions

ABSTRACT

The invention includes a method of forming an aluminum-comprising physical vapor deposition target. An aluminum-comprising mass is deformed by equal channel angular extrusion. The mass is at least 99.99% aluminum and further comprises less than or equal to about 1,000 ppm of one or more dopant materials comprising elements selected from the group consisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo, N, Nb, Nd, Ni, O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Tl, Tm, V, W, Y, Yb, Zn and Zr. After the aluminum-comprising mass is deformed, the mass is shaped into at least a portion of a sputtering target. The invention also encompasses a physical vapor deposition target consisting essentially of aluminum and less than or equal to 1,000 ppm of one or more dopant materials comprising elements selected from the group consisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo, N, Nb, Nd, Ni, O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Ti, Tm, V, W, Y, Yb, Zn and Zr. Additionally, the invention encompasses thin films.

RELATED APPLICATION DATA

[0001] This application claims priority to U.S. provisional applicationSerial No. 60/193,354, which was filed Mar. 28, 2000.

TECHNICAL FIELD

[0002] The invention pertains to methods of forming aluminum-comprisingphysical vapor deposition targets, and to target constructions. Inparticular applications, the invention pertains to methods of utilizingequal channel angular extrusion (ECAE) to deform an aluminum-comprisingmass in forming a physical vapor deposition (PVD) target for use in themanufacture of flat panel displays (FPDs), such as, for example, liquidcrystal displays (LCDs).

BACKGROUND OF THE INVENTION

[0003] PVD is a technology by which thin metallic and/or ceramic layerscan be sputter-deposited onto a substrate. Sputtered materials come froma target, which serves generally as a cathode in a standardradio-frequency (RF) and/or direct current (DC) sputtering apparatus.For example, PVD is widely used in the semiconductor industry to produceintegrated circuits.

[0004] A relatively new application for sputtering technologies isfabrication of FPDs, such as, for example, LCDs. The LCD market hasexperienced rapid growth. This trend may accelerate in the next fewyears due to the diversified applications of LCDs in, for example themarkets of laptop personal computers (PCs), PC monitors, mobile devices,cellular phones and LCD televisions.

[0005] Aluminum can be a particularly useful metal in forming LCDs, andit accordingly can be desired to form aluminum-comprising physical vapordeposition targets. The targets can contain a small content (less thanor equal to about 100 parts per million (ppm)) of doping elements. Thealuminum, with or without small additions of dopants, is generallydesired to be deposited to form a layer of about 300 nm whichconstitutes the reflecting electrode of LCD devices. Several factors areimportant in sputter deposition of a uniform layer of aluminum havingdesired properties for LCD devices. Such factors including: sputteringrate; thin film uniformity; and microstructure. Improvements are desiredin the metallurgy of LCD aluminum targets to improve the above-discussedfactors.

[0006] LCD targets are quite large in size, a typical size being860×910×19 mm³, and are expected to become bigger in the future. Suchmassive dimensions present challenges to the development of tooling andprocessing for fabrication of suitable aluminum-comprising targets.

[0007] Various works demonstrate that three fundamental factors of atarget can influence sputtering performance. The first factor is thegrain size of the material, i.e. the smallest constitutive part of apolycrystalline metal possessing a continuous crystal lattice. Grainsize ranges are usually from several millimeters to a few tenths ofmicrons; depending on metal nature, composition, and processing history.It is believed that finer and more homogeneous grain sizes improve thinfilm uniformity, sputtering yield and deposition rate, while reducingarcing. The second factor is target texture. The continuous crystallattice of each grain is oriented in a specific way relative to theplane of target surface. The sum of all the particular grainorientations defines the overall target orientation. When no particulartarget orientation dominates, the texture is considered to be a randomstructure. Like grain size, crystallographic texture can strongly dependon the preliminary thermomechanical treatment, as well as on the natureand composition of a given metal. Ciystallographic textures caninfluence thin film uniformity and sputtering rate. The third factor isthe size and distribution of structural components, such as second phaseprecipitates and particles, and casting defects (such as, for example,voids or pores). These structural components are usually not desired andcan be sources for arcing as well as contamination of thin films.

[0008] In order to improve the manufacture of LCD targets it would bedesirable to accomplish one or more of the following relative toaluminum-based target materials: (1) to achieve predominate and uniformgrain sizes within the target materials of less than 100 μm; (2) to havethe target materials consist of (or consist essentially of) high purityaluminum (i.e. aluminum of at least 99.99% (4N) purity, and preferablyat least 99.999% (5N) purity, with the percentages being atomicpercentages); (3) to keep oxygen content within the target materialslow; and (4) to achieve large target sizes utilizing the targetmaterials.

[0009] The thermomechanical processes (TMP) used traditionally tofabricate LCD targets can generally only achieve grain sizes larger than200 μm for 5N Al with or without dopants. Such TMP processes involve thedifferent steps of casting, heat treatment, forming by rolling orforging, annealing and final fabrication of the LCD target. Becauseforging and rolling operations change the shape of billets by reducingtheir thickness, practically attainable strains in today's TMP processesare restricted. Further, rolling and forging operations generallyproduce non-uniform straining throughout a billet.

[0010] The optimal method for refining the structure of high purityaluminum alloys (such as, for example, 99.9995% aluminum) would beintensive plastic deformation sufficient to initiate and completeself-recrystallization at room temperature immediately after coldworking.

[0011] High purity aluminum is typically provided as a cast ingot withcoarse dendrite structures (FIG. 1 illustrates a typical structure ofas-cast 99.9995% aluminum). Forging and/or rolling operations areutilized to deform the cast ingots into target blanks. Flat paneldisplay target blanks are optimally to be in the form of large thinplates. The total strains which can be obtained for any combination offorging and/or rolling operations can be expressed as ε=(1−h/H₀)*100%;where H₀ is an ingot length, and h is a target blank thickness.Calculations show that possible thickness reductions for conventionalprocesses range from about 85% to about 92%, depending on target blanksize to thickness ratio. The thickness reduction defines the straininduced in a material. Higher thickness reductions indicate more strain,and accordingly can indicate smaller grain sizes. The conventionalreductions of 85% to 92% can provide static recrystallization of highpurity aluminum (for instance, aluminum having a purity of 99.9995% orgreater) but they are not sufficient to develop the fine and uniformgrain structure desired for flat panel display target materials. Forexample, an average grain size after 95% rolling reduction is about 150microns (such is shown in FIG. 2). Such grain size is larger than thatwhich would optimally be desired for a flat panel display. Further, thestructures achieved by conventional processes are not stable.Specifically, if the structures are heated to a temperature of 150° C.or greater (which is a typical temperature for sputtering operations),the average grain size of the structures can grow to 280 microns or more(see FIG. 3). Such behavior occurs even after intensive forging orrolling.

[0012]FIG. 4 summarizes results obtained for a prior art high purityaluminum material. Specifically, FIG. 4 shows a curve 10 comprising arelationship between a percentage of rolling reduction and grain size(in microns). A solid part of curve 10 shows an effect of rollingreduction on a 99.9995% aluminum material which is selfrecrystallized atroom temperature. As can be seen, even a high rolling reduction of 95%results in an average grain size of about 160 microns (point 12), whichis a relatively coarse and non-uniform structure. Annealing at 150° C.for 1 hour significantly increases the grain size to 270 microns (point14). An increase of reduction to 99% can reduce the grain size to 110microns (point 16 of FIG. 4), but heating to 150° C. for 1 hourincreases the average grain size to 170 microns (point 18 of FIG. 4).

[0013] Attempts have been made to stabilize recrystallized high purityaluminum structures by adding low amounts of different doping elements(such as silicon, titanium and scandium) to the materials. A difficultythat occurs when the doping elements are incorporated is that fullself-recrystallization can generally not be obtained for an entirety ofthe material, and instead partial recrystallization is observed alonggrain boundaries and triple joints. For example, the structure of amaterial comprising 99.9995% aluminum with 30 ppm Si doping is onlypartly recrystallized after rolling with a high reduction of 95% (seeFIG. 6) in contrast to the fully recrystallized structure formed aftersimilar rolling of a pure material (see FIG. 2). Accordingly, additionalannealing of the rolled material at a temperature of 150° C. for about 1hour is typically desired to obtain a fully recrystallized dopedstructure. Such results in coarse and non-uniform grains (see FIG. 7).

[0014] FIG. 5 illustrates data obtained for 99.9995% aluminum with a 30ppm silicon dopant. The curve 20 of FIG. 5 conforms to experimental dataof 99.9995% aluminum with 30 ppm silicon after rolling with differentreductions. A dashed part of the curve 20 corresponds to partialself-recrystallization after rolling, while a solid part of the curvecorresponds to full self-recrystallization. The fullself-recrystallization is attained after intensive reductions of morethan 97%, which are practically not available in commercial targetfabrication processes. The point 22 shows the average grain sizeachieved for the as-deformed material as being about 250 microns, andthe point 24 shows that the grain size reduces to about 180 micronsafter the material is annealed at 150° C. for 1 hour. The points 22 and24 of FIG. 5 correspond to the structures of FIGS. 6 and 7.

[0015] For the reasons discussed above, conventional metal-treatmentprocedures are incapable of developing the fine grain size and stablemicrostructures desired in high purity aluminum target materials forutilization in flat panel display technologies. For instance, adifficulty exists in that conventional deformation techniques are notgenerally capable of forming thermally stable grain sizes of less than150 microns for both doped and non-doped conditions of high puritymetals. Also, particular processing environments can create furtherproblems associated with conventional metal-treatment processes.Specifically, there is a motivation to use cold deformation as much aspossible to refine structure, which can remove advantages of hotprocessing of cast materials for healing pores and voids, and foreliminating other casting defects. Such defects are difficult, if notimpossible, to remove by cold deformation, and some of them can even beenlarged during cold deformation. Accordingly, it would be desirable todevelop methodologies in which casting defects can be removed, and yetwhich achieve desired small grain sizes and stable microstructures.

SUMMARY OF THE INVENTION

[0016] In one aspect, the invention includes a method of forming analuminum-comprising physical vapor deposition target. Analuminum-comprising mass is deformed by equal channel angular extrusion,with the mass being at least 99.99% aluminum and further comprising lessthan or equal to about 1,000 ppm of one or more dopant materialscomprising elements selected from the group consisting of Ac, Ag, As, B,Ba, Be, Bi, C, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf,Ho, In, Ir, La, Lu, Mg, Mn, Mo, N, Nb, Nd, Ni, O, Os, P, Pb, Pd, Pm, Po,Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te,Ti, Tl, Tm, V, W, Y, Yb, Zn and Zr. After the aluminum-comprising massis deformed, the mass is shaped into at least a portion of a sputteringtarget. The sputtering target can ultimately be formed to be either amonolithic or mosaic sputtering target.

[0017] In another aspect, the invention encompasses a method of formingan aluminum-comprising physical vapor deposition target which issuitable for sputtering aluminum-comprising material to form an LCDdevice. An aluminum-comprising mass is deformed by equal channel angularextrusion. After the mass is deformed, it is shaped into at least aportion of a physical vapor deposition target. The physical vapordeposition target has an average grain size of less than or equal to 45microns.

[0018] In yet another aspect, the invention encompasses a physical vapordeposition target consisting essentially of aluminum and less than orequal to 1,000 ppm of one or more dopant materials comprising elementsselected from the group consisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca,Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu,Mg, Mn, Mo, N, Nb, Nd, Ni, O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf,Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Tl, Tm, V, W, Y,Yb, Zn and Zr. The physical vapor deposition target has an average grainsize of less than or equal to 100 microns.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

[0020]FIG. 1 is an optical micrograph of a cast structure of 99.9995%aluminum (magnified 50 times).

[0021]FIG. 2 is an optical micrograph of 99.9995% aluminum showing aself-recrystallized structure after 95% cold rolling reduction(magnified 50 times).

[0022]FIG. 3 is an optical micrograph of 99.9995% aluminum illustratinga structure achieved after 95% cold rolling reduction and annealing at150° C. for 1 hour (magnified 50 times).

[0023]FIG. 4 is a graph illustrating an effect of prior art rollingreduction processes on grain size of 99.9995% aluminum which isself-recrystallized at room temperature.

[0024]FIG. 5 is a graph illustrating the effect of prior art rollingreduction on grain size of a material comprising 99.9995% aluminum with30 ppm Si, with such material being partly self-recrystallized at roomtemperature.

[0025]FIG. 6 is an optical micrograph of 99.9995% aluminum plus 30 ppmSi after 90% cold rolling reduction (magnified 50 times).

[0026]FIG. 7 is an optical micrograph of 99.9995% aluminum plus 30 ppmSi after 90% cold rolling reduction and annealing at 150° C. for 1 hour(magnified 50 times).

[0027]FIG. 8 shows a flow chart diagram of a method encompassed by thepresent invention.

[0028]FIG. 9 is an optical micrograph showing the structure of 99.9995%aluminum after 2 passes through an equal channel angular extrusion(ECAE) device (magnified 50 times).

[0029]FIG. 10 is an optical micrograph of 99.9995% aluminum after 6passes through an ECAE device (magnified 50 times).

[0030]FIG. 11 is a graph illustrating the effect of ECAE on grain sizeof 99.9995% aluminum which is self-recrystallized at room temperature.

[0031]FIG. 12 is a graph illustrating the effect of ECAE passes on grainsize of a material comprising 99.9995% aluminum and 30 ppm Si. The graphillustrates the grain size after self-recrystallization of the materialat room temperature.

[0032]FIG. 13 is an optical micrograph showing the structure of amaterial comprising 99.9995% aluminum and 30 ppm Si after 6 passesthrough an ECAE device (magnified 100 times).

[0033]FIG. 14 is an optical micrograph showing the structure of amaterial comprising 99.9995% aluminum and 30 ppm Si after 6 passesthrough an ECAE device, 85% cold rolling reduction, and annealing at150° C. for 16 hours (magnified 100 times).

[0034]FIGS. 15A and 15B show optical micrographs of a materialcomprising aluminum and 10 ppm Sc after 6 ECAE passes via route D (i.e.,a route corresponding to billet rotation of 90° into a same directionafter each pass through an ECAE device). FIG. 15A shows the material inthe as-deformed state and FIG. 15B shows material after 85% rollingreduction in thickness.

[0035]FIG. 16 is a diagrammatic top-view of a tiled target assemblycomposed of nine billets.

[0036]FIG. 17 is a diagrammatic cross-sectional side-view of the targetassembly of FIG. 16 shown along the line 17-17.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] A deformation technique known as equal channel angular extrusion(ECAE) is used with advantage for the manufacture of physical vapordeposition targets, and in particular aspects of the invention isutilized for the first time in the manufacture of FPD and LCD targets.The ECAE technique was developed by V. M. Segal, and is described inU.S. Pat. Nos. 5,400,633; 5,513,512; 5,600,989; and 5,590,390. Thedisclosure of the aforementioned patents is expressly incorporatedherein by reference.

[0038] The general principle of ECAE is to utilize two intersectingchannels of approximately identical cross-section and extrude a billetthrough the channels to induce deformations within the billet. Theintersecting channels are preferably exactly identical in cross-sectionto the extent that “exactly identical” can be measured and fabricatedinto an ECAE apparatus. However, the term “approximately identical” isutilized herein to indicate that the cross-sections may be close toexactly identical, instead of exactly identical, due to, for example,limitations in fabrication technology utilized to form the intersectingchannels.

[0039] An ECAE apparatus induces plastic deformation in a materialpassed through the apparatus. Plastic deformation is realized by simpleshear, layer after layer, in a thin zone at a crossing plane of theintersecting channels of the apparatus. A useful feature of ECAE is thatthe billet shape and dimensions remain substantially unchanged duringprocessing (with term “substantially unchanged” indicating that thedimensions remain unchanged to the extent that the intersecting channelshave exactly identical cross-sections, and further indicating that thechannels may not have exactly identical cross-sections).

[0040] The ECAE technique can have numerous advantages. Such advantagescan include: strictly uniform and homogeneous straining; highdeformation per pass; high accumulated strains achieved with multiplepasses; different deformation routes, (i.e., changing of billetorientation at each pass of multiple passes can enable creation ofvarious textures and microstructures); and low load and pressure.

[0041] ECAE can enable a decrease in the grain size of high purityaluminum and aluminum alloys used for the manufacture of LCDs by atleast a factor of three compared to conventional practices.

[0042] Various aspects of the present invention are significantlydifferent from previous ECAE applications. Among the differences is thatthe present invention encompasses utilization of ECAE to deform highpurity materials (such as, for example, aluminum having a purity ofgreater than 99.9995% as desired for FPD targets), in contrast to themetals and alloys that have previously been treated by ECAE. High puritymetals are typically not heat treatable, and ordinary processing stepslike homogenizing, solutionizing and aging can be difficult, if notimpossible, to satisfactorily apply with high purity metals. Further,the addition of low concentrations of dopants (i.e., the addition ofless than 100 ppm of dopants) doesn't eliminate the difficultiesencountered in working with high purity metals. However, the presentinvention recognizes that a method for controlling structure ofsingle-phase high purity materials is a thermo-mechanical treatment bydeformation, annealing and recrystallization. Also, as high puritymetals are generally not stable and cannot be refined by dynamicrecrystallization in the same manner as alloys, the present inventionrecognizes that static recrystallization can be a more appropriatemethodology for annealing of high purity metals than dynamicrecrystallization. When utilizing static recrystallization annealing ofmaterials, it is preferred that the static recrystallization beconducted at the lowest temperature which will provide a fine grainsize. If strain is increased to a high level within a material, such canreduce a static recrystallization temperature, with high strains leadingto materials which can be statically recrystallized at room temperature.Thus, self-recrystallization of the materials can occur immediatelyafter a cold working process. Such can be an optimal mechanism forinducing desired grain sizes, textures, and other microstructures withinhigh purity metal physical vapor deposition target structures.

[0043] In one aspect, the present invention utilizes ECAE to form aphysical vapor deposition target for LCD applications. The targetcomprises a body of aluminum with a purity greater than or equal to99.99% (4N). The aluminum can be doped with less than or equal to about1000 ppm of dopant materials. The dopant materials are not consideredimpurities relative to the doped aluminum, and accordingly the dopantconcentrations are not considered in determining the purity of thealuminum. In other words, the percent purity of the aluminum does notfactor in any dopant concentrations.

[0044] An exemplary target can comprise a body of aluminum having apurity greater than or equal to 99.9995%. A total amount of dopantmaterial within the aluminum is typically between 5 ppm and 1,000 ppm,and more preferably between 10 ppm and 100 ppm. The amount of dopingshould be at least the minimal amount assuring the stability of materialmicrostructures during sputtering, and less than the minimum amounthindering the completion of full dynamic recrystallization during equalchannel angular extrusion.

[0045] The dopant materials can, for example, comprise one or moreelements selected from the group consisting of Ge, Group IIA elements,Group IIIA elements, Group VIA elements, Group VA elements, Group IIIBelements, Group IVB elements, Group VIB elements, Group VIII elements,and Rare Earth elements. Alternatively, the dopant materials cancomprise one or more of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd, Ce, Co,Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo,N, Nb, Nd, Ni, O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S,Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Ti, Tm, V, W, Y, Yb, Zn andZr.

[0046] The elements of the dopant materials can be in either elementalor compound form within the materials. The dopant materials can beconsidered to comprise two different groups of materials. The firstgroup comprises dopant materials having effectively no room temperaturesolid solubility relative to an aluminum matrix, and having nointermediate compounds. Such first type of dopant materials are Be, Geand Si. The second type of dopant materials have effectively no roomtemperature solid solubility in aluminum, and are not toxic, refractoryor precious metals, and further possess relatively high meltingtemperatures. The second type of materials include various elementsselected from the Group IIA elements; the Group IIIB elements; the GroupIVB elements; the Group VIB elements; the Group VIII elements; the GroupIIIA elements; the Group VA elements; the Group VIA elements, and theRare Earth elements (i.e., the lanthanides).

[0047] The dopant materials can be in the form of precipitates or solidsolutions within the aluminum-material matrix. Preferably, the target iscomposed of aluminum with purity greater than or equal to 99.99% (4N),and with one or more dopant materials comprising elements selected fromthe group consisting of Si, Sc, Ti, and Hf.

[0048] The present invention can provide a physical vapor depositiontarget for LCD applications comprising a body of aluminum with puritygreater than or equal to 99.99% (4N), alone or doped with less than 1000ppm of dissimilar elements selected from a group consisting of one ormore of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er,Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo, N, Nb, Nd, Ni,O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb, Sc, Se, Si,Sm, Sn, Sr, Ta, Tb, Te, Ti, TI, Tm, V, W, Y, Yb, Zn and Zr. Further thetarget can consist of aluminum and one or more of the listed dissimilarelements, or can consist essentially of aluminum and the one or more ofthe listed dissimilar elements.

[0049] The LCD target can be made of a body of Al with purity greaterthan 99.99% (4N), alone or doped with less 100 ppm of one or moredissimilar elements listed above, and the total doping content of anyelement listed above can be higher than the solubility limit of thiselement at the temperature at which ECAE is performed.

[0050] Particularly preferred materials for LCD targets consist of Aland less than 100 ppm of Si; Al and less than 100 ppm of Sc; Al and lessthan 100 ppm of Ti; or Al and less than 100 ppm of Hf.

[0051] A preferred LCD target possesses: a substantially homogeneouscomposition throughout; a substantial absence of pores, voids,inclusions and any other casting defects; a predominate and controlledgrain size of less than about 50 micrometers; and a substantiallyuniform-structure and controlled texture throughout. Very fine anduniform precipitates with average grain diameters of less than 0.5micrometers can also be present in a preferred target microstructure.

[0052] LCD physical vapor deposition targets of the present inventioncan be formed from a cast ingot comprising, consisting of, or consistingessentially of aluminum. The aluminum material can be extruded through adie possessing two contiguous channels of equal cross sectionintersecting each other at a certain angle. The ingot material can alsobe subjected to annealing and/or processing with conventionaltarget-forming processes such as rolling, cross-rolling or forging, andultimately fabricated into a physical vapor deposition target shape. Theextrusion step can be repeated several times via different deformationroutes before final annealing, conventional processing and fabricationsteps to produce very fine and uniform grain sizes within a processedmaterial, as well as to control texture strength and orientation withinthe material.

[0053] Processes of the present invention can be applied to large flatpanel display monolithic targets, or targets comprised of two or moresegments.

[0054] Particular embodiments of the present invention pertain toformation of aluminum-comprising physical vapor deposition targets, suchas, for example, formation of aluminum-comprising physical vapordeposition targets suitable for liquid crystal display (LCD)applications. FIG. 8 shows a flow-chart diagram of an exemplary processof the present invention. In a first step, an aluminum-comprising castingot is formed, and in a second step the ingot is subjected tothermo-mechanical processing. The material resulting from thethermo-mechanical processing is an aluminum-comprising mass. The mass issubsequently deformed by equal channel angular extrusion (ECAE). Suchdeformation can be accomplished by one or more passes through an ECAEapparatus. Exemplary ECAE apparatuses are described in U.S. Pat. Nos.5,400,633; 5,513,512; 5,600,989; and 5,590,390. The aluminum-comprisingmass can consist of aluminum, or can consist essentially of aluminum.The mass preferably comprises at least 99.99% aluminum. The mass canfurther comprise less than or equal to about 100 parts per million (ppm)of one or more dopant materials comprising elements selected from thegroup consisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd, Ce, Co, Cr,Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo, N,Nb, Nd, Ni, O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb,Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Tl, Tm, V, W, Y, Yb, Zn and Zr.The aluminum-comprising mass can consist of aluminum with less than orequal to about 100 ppm of one or more of the dopant materials describedabove, or consist essentially of aluminum with less than or equal toabout 100 ppm of one or more of the dopant materials described above.

[0055] ECAE is utilized in methodology of the present invention foraddressing problems found during formation of PVD targets of high-puritymaterials. ECAE is a process which utilizes a simple shear deformationmode, which is different from a dominant deformation mode achieved byuniaxial compression of forging or rolling. In high purity metals, theintensive simple shear of ECAE can manifest itself by developing verythin and long shear bands. The strains achieved inside these bands canbe many times larger than the strains achieved outside the bands. Theshear bands occur along a crossing plane of the channels utilized duringECAE. If a processing speed is sufficiently low to eliminate adiabaticheating and flow localization at the macro-scale, shear bands in puremetals can have a thickness of only a few microns with a near regularspacing between each other of a few tenths of a micron. The bands can beobserved after a single ECAE pass. However, if the number of ECAE passesincreases the spacing between shear bands can reduce to a stable size.The actual size can vary depending on the material being subjected toECAE, and the purity of such material. A strain inside of the shearbands can be equivalent to very high reductions (specifically,reductions of about 99.99% or more), and static recrystallization isimmediately developed in the bands. The static recrystallization canlead to new fine grains growing in spacing between the bands.

[0056]FIGS. 9 and 10 show fully recrystallized structures of 99.9995%aluminum after ECAE with 2 passes and 6 passes, respectively. The grainswithin the material attained a stable size after 6 passes. Experimentshave shown that processing with a route corresponding to billet rotationof 90° into a same direction after each pass can provide the mostuniform and equiaxial recrystallized structures for high puritymaterials. Such route is defined as route “D” in accordance with thestandard definitions that have been utilized to described ECAEprocessing in previous publications.

[0057]FIG. 11 shows a curve 30 demonstrating the change manifested ingrain size of a high-purity aluminum material subjected to varyingnumbers of ECAE passes. Curve 30 of FIG. 11 can be compared with thecurve 10 of FIG. 4 to illustrate advantages in grain size reductionsattained by an ECAE process relative to the conventional processesutilized to generate the curve 10 of FIG. 4.

[0058] The ECAE structures are found to not only have small grain sizes,but also to be stable during additional annealing to sputtering-typetemperatures. For example, after annealing at 150° C. for 1 hour, amaterial subjected to six ECAE passes shows only a relativelyinsignificant increase in grain size of from 40 microns (point 32 inFIG. 11) to 50 microns (point 34 in FIG. 11). However, the structuresdiagrammed at FIG. 11 were found to be relatively unstable whensubjected to rolling procedures, even when the rolling proceduresaccomplished only moderate reductions. For instance, a significantincrease of grain size from 40 microns after 6 ECAE passes to 160microns occurred after rolling with the reduction of 75% (point 36 onFIG. 11).

[0059] Generally, ECAE can be effectively performed only when a ratio ofbillet size to thickness is from about 4 to 8, while flat panel displaytargets typically have a ratio of up to 100 or more. Accordingly,additional rolling of ECAE processed billets may be desired to fabricatethe thin targets desired for FPD. Thus, it would be desirable to developmethodologies which avoided the structure coarsening evidenced by point36 of FIG. 11. One way to avoid such structure coarsening is toeliminate rolling. This can be achieved if an ECAE processed billet hasa sufficiently large size to fabricate FPD targets by splitting thebillet thickness for a number of thin plates. However, this can be acomplicated process since FPD targets have a typical size of 1000millimeters, or larger; and ECAE of such large billets is typically notpractical. Another method for incorporating ECAE processed billets intoFPD targets is to fabricate mosaic targets by using a large number ofsmall pieces cut from ECAE billets (see, for example, FIGS. 16 and 17).However, mosaic targets are typically expensive to fabricate, and alsotypically do not provide good performance in sputtering applications.

[0060] Another method which can be utilized to avoid grain size growthwithin ECAE processed materials is to provide doping elements within theECAE materials. However, while the addition of dopants can typically beutilized for structure refinement when static recrystallization isperformed as a separate annealing operation at sufficiently hightemperatures after mechanical working, it cannot generally be applied inthe case of self-annealing at room temperature during or immediatelyafter deformation performed by forging or rolling because the doping canmake even heavily deformed structures more stable.

[0061] ECAE can be utilized for grain refinement of high purity metals,even if the metals have some dopant material therein. For instance,99.9995% aluminum having 30 ppm of silicon therein is found to be almostfully recrystallized after 2 passes through an ECAE apparatus. If thematerial is subjected to 3 to 6 passes through the apparatus, it isfound to have a fine and uniform structure, with such structureremaining substantially unchanged after 6 passes through the device.FIG. 12 illustrates a curve 50 corresponding to the change in grain sizeof 99.9995% aluminum having 30 ppm silicon therein, with various numbersof ECAE passes. A dashed part of curve 50 corresponds to partialrecrystallization, and a solid part of curve 50 corresponds to fullrecrystallization at room temperature immediately after ECAE.

[0062] The structure after 6 passes is illustrated in FIG. 13. Suchstructure is a substantially perfectly recrystallized, uniform, veryfine and equiaxial structure having an average grain size of about 15microns. Such properties can provide exceptional stability of thestructure during subsequent rolling and annealing. For instance,subsequent rolling with a reduction of up to 90%, and long-termannealing of about 16 hours at a temperature of 150° C. causes only amoderate grain growth, with the resulting structure having an averagegrain size of about 30 microns. Further, structure uniformity ismaintained, as illustrated in the optical micrograph of FIG. 14. Suchstability of the small grain size microstructures achieved with ECAE issubstantially different than what can be accomplished with conventionalprocesses of forging, rolling or other deformation techniques.Accordingly, ECAE can provide improved methodology for fabricating highpurity targets with fine and stable microstructures for physical vapordeposition applications. It is found that ECAE processing utilizing from3 to 6 passes through an ECAE device is typically suitable for forming aphysical vapor deposition target blank. In particular, ECAE with 4passes of route “D” (i.e., rotation of 90° into the same direction aftereach pass) can be an optimal processing schedule.

[0063] Experiments have been performed on doping selection andconcentration. Specifically, the doping elements Si, Sc and Ti have beentested. Concentrations ranged from 5 ppm to 100 ppm for each of theelements. In all of the tested cases, the effects achieved with theelements were found to be qualitatively about the same, with somequantitative differences. For instance, it was found that silicon dopingcan provide the best refinement, provided that a doping concentration isfrom about 5 ppm to about 100 ppm.

[0064] Among the benefits of utilizing ECAE for forming target blanks ofhigh-purity materials, relative to utilizing conventional processes, isthat ECAE can be utilized in combination with a hot-forging operation.Specifically, ECAE removes restrictions on attainable deformation duringprocessing from a cast ingot to a target blank, and accordingly removesrequirements on the original structures subjected to ECAE. A materialcan be subjected to hot forging prior to ECAE. Such hot forging canresult in substantially entire elimination of casting defects, which canfurther result in improved performance of targets formed by methodologyof the present invention relative to targets formed by conventionalprocesses.

[0065] In a fourth step of the FIG. 8 flow-chart diagram, the deformedaluminum-comprising mass is shaped into a PVD target, or at least aportion of a target. Such shaping can comprise, for example, one or moreof rolling, cross-rolling, forging, and cutting of thealuminum-comprising mass. The mass can be formed into a shape comprisingan entirety of a physical vapor deposition target, or alternatively canbe formed into a shape comprising only a portion of a physical vapordeposition target. An exemplary application wherein the mass is formedinto a shape comprising only a portion of a physical vapor depositiontarget is an application in which the mass is utilized to form part of aso-called mosaic target. If the aluminum-comprising mass is utilized ina mosaic target, and further utilized for LCD applications, it can bedesired that all of the various target portions of the mosaic target bealuminum-comprising masses which have been deformed by equal channelangular extrusion prior to incorporation into the mosaic target.

[0066] In the fifth step of the FIG. 8 process, the shaped mass ismounted to a backing plate to incorporate the mass into a targetstructure. Suitable backing plates and methodologies for mountingaluminum-comprising targets to backing plates are known in the art. Itis noted that the invention encompasses embodiments wherein analuminum-comprising mass is utilized directly as a physical vapordeposition target without being first mounted to a backing plate, aswell as embodiments in which the mass is mounted to a backing plate.

[0067] Processes of the present invention can be utilized to fabricatealuminum-comprising masses into targets having very fine and homogenousgrain structures, with predominate sizes of the grains being less thanabout 50 micrometers. Such targets can be particularly suitable forsputtering applications in forming LCD materials. The present inventionrecognizes that improvements in grain refinement can be provided by ECAEtechnology relative to processing of aluminum-comprising materials. TheECAE is preferably conducted at a temperature and speed sufficient toachieve desired microstructures and provide a uniform stress-strainstate throughout a processed billet.

[0068] The number of passes through an ECAE device, and the particularECAE deformation route selected for travel through the device can bechosen to optimize target microstructures. For instance, grainrefinement can be a consequence of radical structural transformationsoccurring during intense straining by simple shear through an ECAEdevice.

[0069]FIGS. 15A illustrates grains obtained for aluminum +10 ppm Scafter ECAE processing. The grains shown in FIG. 15A have an average sizeof about 20 microns, and are relatively fine, equiaxial, and homogenous.The structure shown in FIG. 15A has an average grain size that is atleast a factor of 3 smaller than the sizes produced by conventionaltarget-forming methods.

[0070] At least three different aspects of ECAE contribute to theremarkable reduction of grain size and improvement of grain uniformityachieved by treating aluminum-comprising masses in accordance with thepresent invention. These three aspects are an amount of plasticdeformation imparted by ECAE, the ECAE deformation route, and simpleshear forces occurring during ECAE.

[0071] After a material has been subjected to ECAE in accordance withmethods of the present invention, the material can be shaped byconventional methods of forging, cross-rolling and rolling to form thematerial into a suitable shape to be utilized as a target in asputtering process. The ultrafine grain sizes created during ECAE arefound to remain stable and uniform, and to show limited grain growthupon further conventional processing; even during processing comprisinga high reduction in thickness of a material. Such is exemplified by FIG.15, which compares various microstructures of as-deformed ECAE samples(FIG. 15A) to those submitted to further unidirectional rolling at an85% thickness reduction (FIG. 15B) for aluminum+10 ppm Sc.

[0072] Preferably, traditional forming operations-utilized for shaping amaterial after ECAE processing are conducted at temperatures which areless than those which will occur during sputtering. For instance, ifsputtering processes are anticipated to occur at about 150° C., thenconventional processing of, for example, rolling, cross-rolling, orforging occurring after ECAE will preferably occur at temperatures below150° C. By conducting such processing at temperatures below thesputtering temperature, the likelihood of the conventional processingincreasing grain sizes beyond those desired in a physical vapordeposition target is reduced. Typically, target shaping steps occur attemperatures of less than or equal to about 200° C., and more preferablyoccur at temperatures less than or equal to about 150° C., to keep thetarget shaping steps at temperatures below an ultimate sputteringtemperature of a target.

[0073] The microstructures created during ECAE are found to exhibitexceptional stability upon annealing relative to microstructures createdby conventional processes. For example, it is found that a sample ofaluminum+30 ppm Si which has been subjected to ECAE shows a limited andprogressive increase in average grain size from approximately 12 micronsto about 30 microns after annealing at 150° C. for 1 hour. Such averagegrain size does not significantly change after annealing at 150° C. for16 hours. In contrast, samples submitted solely to rolling to an 85%reduction in thickness (a conventional process), show a dramatic graingrowth up to average grain sizes larger than 250 micron after annealingat only 125° C. for 1 hour.

[0074] Utilization of ECAE for processing aluminum targets can enablecontrol of a texture within the targets, with the term “texture”referring to a crystallographic orientation within the target. If alarge number (i.e. a vast majority) of the grains in a material have thesame crystallographic orientation as one another, the material isreferred to as having strong texture. In contrast, if the grains do nothave the same crystallographic orientation, the material is referred toas having a weak texture. Note that the referred-to crystallographicorientation is not to imply that the grains are part of a singlecrystal. Various textures can be created utilizing methodology of thepresent invention.

[0075] A particular application of the invention is directed to themanufacture of targets of especially large size. FIGS. 16 and 17 displaythis aspect of the invention. In FIGS. 16 and 17, the construction of atarget 190 in the form of a tiled assembly is provided. Such comprisesjoining two or more billets 200 of identical shape, dimensions andprocessing history to a backing plate 210, machining the surface of theresulting assembly, and fabricating the final target 190. Preferably,the backing plate is made of a high strength material and possesses alength and width close to those of the final target. Joining is realizedby known methods such as soldering, brazing, welding or diffusionbonding at an interface 220 between the backing plate and the bottom ofeach single billet and at sufficient time, pressure and temperature.Preferably, techniques such as brazing or soldering will be used becausethey can utilize lower temperatures than some of the other methods.Also, lateral forces along the three different directions X, Y and Zshown in FIGS. 16 and 17 are exerted with appropriate tooling. Theforces along the directions X and Y keep all the billets held tightlytogether, while the force along the Z direction participates to thejoining operations and keeps the surface of the final target flat. Also,as shown in FIGS. 16 and 17, one side of the bottom of each billet ispreferably machined to leave a space 230 at the bottom between adjacentbillets. Such space can have materials provided therein which are usedfor joining the billets together (the space is shown in dashed-linephantom view in FIG. 16). This space can also prevent the materialsutilized for soldering, brazing, welding and diffusion bonding fromgoing between billets and contaminating the target surface and thevolume to be sputtered.

[0076] The method described with reference to FIGS. 16 and 17 canpresent several advantages for the production of very large targets.First, current equipment and tooling can be employed. Second, contraryto current known methods, intensive rolling and/or cross-rolling are notused to reach final target size; therefore, for example, as-deformedECAE billets can be directly joined together and retain their advantagesin terms of grain size and texture. Third, the procedure is easilyadaptable to any future evolution of the size of LCD targets.

EXAMPLES Example 1 High-Purity Aluminum Having 30 ppm Si Therein, andProcessed in Accordance with Methodology of the Present Invention

[0077] As-cast material defined as 5N5 Al and 30 ppm Si is processed viahot forging at 75% reduction and ECAE for 6 passes via route D. Thematerial has a fully recrystallized structure with grain size of 15 μm.Subsequent rolling with a reduction of 85% grew the average grain sizeto 20 μm with an aspect ratio of about 1.5. Annealing at a temperatureof 150° C. for 1 hour, which was estimated as the highest temperatureexpected during a subsequent sputtering process, resulted in aninsignificant grain growth to 23 μm. During a long (16 hours) exposureto 150° C., grains grew to 28 μm. Also, a temperature increase to 200°C. for 1 hour yielded a similar grain size of about 30 μm. Therefore,ECAE plus rolling provides a fine and uniform structure for a materialof 5N5 Al and 30 ppm Si, with an average grain size of less than orequal to about 30 μm which is stable for sputtering target applications.

Example 2 High-Purity Aluminum Having 10 ppm Silicon Therein, andProcessed in Accordance with Methodology of the Present Invention

[0078] Samples were cast, hot forged at 74% reduction and ECAE extrudedfor 6 passes via route D. A Structure after ECAE is fully dynamicallyrecrystallized with an average grain size of about 19 μm. Subsequentrolling at 85%, and annealing at 150° C. for 1 hour yields a fullyrecrystallized grain size of around 35 um.

Example 3 High-Purity Aluminum Having 10 ppm Sc Therein, and Processedin Accordance with Methodology of the Present Invention

[0079] Samples were cast, hot forged at 74% reduction, and ECAE extrudedfor 6 passes via route D. A structure after ECAE is fully dynamicallyrecrystallized with an average grain size of about 26 μm. During rollingup to a reduction of 60%, the structure remains stable and typical forheavily-rolled materials. After 70% reduction, first recrystallizedgrains are observed. At 85% rolling reduction, about 60% of the samplearea was fully recrystallized with an average grain size of about 45 μm.

Example 4 Aluminum Having 30 ppm Silicon Therein, and Processed inAccordance with Prior Art Technologies

[0080] The present example was run to allow comparison of previousresults of ECAE (examples 1-3) with data obtained utilizing conventionalprocessing technologies. The same 5N5 Al+30 ppm Si material was used forthis example as was used in Example 1. A cast, hot forged at 74%reduction and annealed sample was subsequently cold rolled with areduction of 85%. Its structure is not fully recrystallized and finedynamically recrystallized grains can be observed only along boundariesof original grains. Additional annealing at 125° C. for 1 hour providesfull recrystallization but the microstructure has a highly non-uniformdistribution with an average grain size of about 150 μm. Annealing athigher temperatures further increases the average grain size. Theexample illustrates that conventional processing techniques only providea moderate refinement of the structure of 5N5 Al with 30 ppm Si doping.Specifically, the grain size achieved is well above a desired limit of100 μm, and, in fact, is greater than 150 μm.

[0081] In compliance with the statute, the invention has been describedin language more or less specific as to structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred forms of putting the invention intoeffect. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A method of forming an aluminum-comprising physical vapor depositiontarget, comprising: deforming an aluminum-comprising mass by equalchannel angular extrusion, wherein the mass is at least 99.99% aluminumand further comprises less than or equal to about 1000 ppm of one ormore dopant materials comprising elements selected from the groupconsisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd, Ce, Co, Cr, Cu, Dy,Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo, N, Nb, Nd,Ni, O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb, Sc, Se,Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Tl, Tm, V, W, Y, Yb, Zn and Zr; afterthe deforming, shaping the mass into at least a portion of a physicalvapor deposition target.
 2. The method of claim 1 wherein the physicalvapor deposition target is a monolithic target.
 3. The method of claim 1wherein the one or more dopant materials comprise materials selectedfrom the group consisting of B, Ba, Be, Ca, Ce, Co, Cr, Dy, Er, Eu, Gd,Ge, Hf, Ho, La, Ni, Nd, Pd, Pm, Pr, Sb, Sc, Si, Sm, Sr, Tb, Te, Ti, Tm,Y, Yb and Zr.
 4. The method of claim 1 wherein the one or more dopantmaterials comprise materials selected from the group consisting of Si,Sc, Ti and Hf.
 5. The method of claim 1 wherein the mass consists ofaluminum and from about 10 ppm to about 100 ppm of the one or moredopant elements.
 6. The method of claim 1 wherein the mass consists ofAl and from about 10 ppm to about 100 ppm of one or more of Si, Sc, Ti,and Hf.
 7. The method of claim 1 wherein the mass consists of Al andfrom about 10 ppm to about 100 ppm of Hf.
 8. The method of claim 1wherein the mass consists of Al and from about 10 ppm to about 100 ppmof Ti.
 9. The method of claim 1 wherein the mass consists of Al and fromabout 10 ppm to about 100 ppm of Sc.
 10. The method of claim 1 whereinthe mass consists of Al and from about 10 ppm to about 100 ppm of Si.11. A method of forming an aluminum-comprising physical vapor depositiontarget, comprising: deforming an aluminum-comprising mass by equalchannel angular extrusion; and after the deforming, shaping the massinto at least a portion of a physical vapor deposition target, thephysical vapor deposition target having an average grain size less thanor equal to 45 microns.
 12. The method of claim 11 wherein the mass isformed into an entirety of the physical vapor deposition target, andfurther comprising mounting the mass to a backing plate.
 13. The methodof claim 11 wherein the mass is at least 99.99% aluminum and consists ofAl and less than 100 ppm of one or more of Si, Sc, Ti and Hf.
 14. Themethod of claim 11 wherein the mass is at least 99.99% aluminum, andfurther comprises greater than 0 ppm and less than or equal to about 100ppm of one or more dopant materials comprising elements selected fromthe group consisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd, Ce, Co,Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo,N, Nb, Nd, Ni, O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S,Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Ti, Tm, V, W, Y, Yb, Zn andZr.
 15. The method of claim 11 wherein the mass consists essentially ofaluminum.
 16. The method of claim 11 wherein the mass consistsessentially of aluminum, and less than or equal to about 100 ppm of oneor more dopant materials comprising elements selected from the groupconsisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd, Ce, Co, Cr, Cu, Dy,Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo, N, Nb, Nd,Ni, O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb, Sc, Se,Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, TI, Tm, V, W, Y, Yb, Zn and Zr.
 17. Themethod of claim 11 wherein the shaping comprises one or more of forgingand rolling of the aluminum-comprising mass at a temperature of lessthan or equal to about 200° C.
 18. The method of claim 11 wherein thedeforming comprises at least three extruding steps, each of the at leastthree extruding steps comprising passing the mass through twointersecting passages having approximately equal cross-sections.
 19. Themethod of claim 11 wherein the deforming comprises at least fourextruding steps, each of the at least four extruding steps comprisingpassing the mass through two intersecting passages having approximatelyequal cross-sections.
 20. The method of claim 11 wherein the deformingcomprises at least six extruding steps, each of the at least sixextruding steps comprising passing the mass through two intersectingpassages having approximately equal cross-sections.
 21. A physical vapordeposition target consisting essentially of aluminum and less than orequal to 1000 ppm of one or more dopant materials comprising elementsselected from the group consisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca,Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu,Mg, Mn, Mo, N, Nb, Nd, Ni, O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf,Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Tl, Tm, V, W, Y,Yb, Zn and Zr; the physical vapor deposition target having an averagegrain size of less than 100 microns.
 22. The physical vapor depositiontarget of claim 21 having an average grain size of less than or equal to45 microns.
 23. The physical vapor deposition target of claim 21consisting of Al and less than 100 ppm of one or more of Si, Sc, Ti; andHf.
 24. The physical vapor deposition target of claim 21 consisting ofAl and from 10 ppm to 100 ppm of one or more of Si, Sc, Ti; and Hf. 25.The physical vapor deposition target of claim 21 consisting of Al andfrom 10 ppm to 100 ppm of Sc; the target having an average grain size ofless than or equal to 45 microns.
 26. The physical vapor depositiontarget of claim 21 consisting of Al and from 10 ppm to 100 ppm of Si;the target having an average grain size of less than or equal to 35microns.
 27. The physical vapor deposition target of claim 21 consistingof Al and from 10 ppm to 100 ppm of Ti.
 28. The physical vapordeposition target of claim 21 consisting of Al and from 10 ppm to 100ppm of Hf.
 29. A film sputtered-from a target, the film consistingessentially of aluminum and less than or equal to 1000 ppm of one ormore dopant materials comprising elements selected from the groupconsisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd, Ce, Co, Cr, Cu, Dy,Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo, N, Nb, Nd,Ni, O, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb, Sc, Se,Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Tl, Tm, V, W, Y, Yb, Zn and Zr.
 30. Thefilm of claim 29 consisting of Al and less than 100 ppm of one or moreof Si, Sc, Ti and Hf.
 31. The film of claim 29 consisting of Al and from10 ppm to 100 ppm of one or more of Si, Sc, Ti and Hf.